diff options
Diffstat (limited to 'drivers/acpi/osl.c')
| -rw-r--r-- | drivers/acpi/osl.c | 20 |
1 files changed, 17 insertions, 3 deletions
diff --git a/drivers/acpi/osl.c b/drivers/acpi/osl.c index 9c0edf2fc0dd..a2e844a8e9ed 100644 --- a/drivers/acpi/osl.c +++ b/drivers/acpi/osl.c @@ -14,6 +14,7 @@ #include <linux/slab.h> #include <linux/mm.h> #include <linux/highmem.h> +#include <linux/lockdep.h> #include <linux/pci.h> #include <linux/interrupt.h> #include <linux/kmod.h> @@ -26,6 +27,7 @@ #include <linux/list.h> #include <linux/jiffies.h> #include <linux/semaphore.h> +#include <linux/security.h> #include <asm/io.h> #include <linux/uaccess.h> @@ -80,6 +82,7 @@ struct acpi_ioremap { static LIST_HEAD(acpi_ioremaps); static DEFINE_MUTEX(acpi_ioremap_lock); +#define acpi_ioremap_lock_held() lock_is_held(&acpi_ioremap_lock.dep_map) static void __init acpi_request_region (struct acpi_generic_address *gas, unsigned int length, char *desc) @@ -180,8 +183,19 @@ acpi_physical_address __init acpi_os_get_root_pointer(void) acpi_physical_address pa; #ifdef CONFIG_KEXEC - if (acpi_rsdp) + /* + * We may have been provided with an RSDP on the command line, + * but if a malicious user has done so they may be pointing us + * at modified ACPI tables that could alter kernel behaviour - + * so, we check the lockdown status before making use of + * it. If we trust it then also stash it in an architecture + * specific location (if appropriate) so it can be carried + * over further kexec()s. + */ + if (acpi_rsdp && !security_locked_down(LOCKDOWN_ACPI_TABLES)) { + acpi_arch_set_root_pointer(acpi_rsdp); return acpi_rsdp; + } #endif pa = acpi_arch_get_root_pointer(); if (pa) @@ -206,7 +220,7 @@ acpi_map_lookup(acpi_physical_address phys, acpi_size size) { struct acpi_ioremap *map; - list_for_each_entry_rcu(map, &acpi_ioremaps, list) + list_for_each_entry_rcu(map, &acpi_ioremaps, list, acpi_ioremap_lock_held()) if (map->phys <= phys && phys + size <= map->phys + map->size) return map; @@ -249,7 +263,7 @@ acpi_map_lookup_virt(void __iomem *virt, acpi_size size) { struct acpi_ioremap *map; - list_for_each_entry_rcu(map, &acpi_ioremaps, list) + list_for_each_entry_rcu(map, &acpi_ioremaps, list, acpi_ioremap_lock_held()) if (map->virt <= virt && virt + size <= map->virt + map->size) return map; |